The MP has flagged up the issues following a meeting with officers at the prison, amid concerns over arrangements there since it was privatised and jobs were cut late last year.

Sir Alan said some wings are manned by only two workers, and that prisoners can move between their cells and workshops along unsupervised routes.

He said officers have told him there had been an increase in incidents of disorder, but that staff are “discouraged” from challenging disruptive behaviour, which would require them to fill in specialist behaviour reports.

HMP Northumberland was formed by the merger of Castington and Acklington jails in 2011. The category C 1,300-inmate jail, which houses vulnerable sex offenders, was taken over by French firm Sodexo under a Government privatisation programme on December 1.

On Friday evening, more than 50 prisoners sparked a disturbance. Reports suggest there was a stand-off, with inmates reportedly refusing to go back to their cells and riot officers on standby. It is not believed anyone was injured.

The incident has brought renewed concerns over security at the prison following the staff cuts.

Sir Alan said: “I have sent a series of urgent and detailed questions to Sodexo and the Prisons Minister following last Friday’s incident. I have asked what lessons have been learned from the incident and whether prison safety can be retained with such a large reduction in staffing.

“If you get a bit of uncertainty in a prison and uncertainty among officers, there is always the chance prisoners might try to take advantage of that.

“I have raised with the minister the issue of whether compliance with the original contract is being met and whether the terms of the contract are sufficient for the security of the prison.”

Earlier this week, Sodexo said it had “no concerns” over staffing levels at the prison.

The company is investigating Friday’s incident and in a statement yesterday said: “We congratulate all the staff involved in the incident for the professional way in which they resolved the situation.”

It continued: “There was minimal damage to the affected area and the prison returned to its normal regime by Saturday morning.” Wansbeck MP Ian Lavery raised concerns in Parliament about staffing levels at the prison last month.

Responding at the time, justice minister Chris Grayling said: “We are having to take difficult decisions about staffing levels across the prison estate.

“I am confident that every one of our prisons is a safe place to detain prisoners.”